:root {
  --ink: #1c1915;
  --muted: #6a645c;
  --line: #e6e0d6;
  --paper: #f4f1ea;
  --card: #fffcf8;
  --mark: #2f4a3c;
  --head: #fbfaf7;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Yu Gothic", "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  line-height: 1.85;
  font-size: 16.5px;
}
a { color: var(--mark); text-underline-offset: 0.18em; }
header.site {
  background: var(--head);
  border-bottom: 1px solid var(--line);
}
.top {
  max-width: 44rem;
  margin: 0 auto;
  padding: 1.15rem 1.25rem 0.9rem;
}
.brand {
  color: var(--ink);
  text-decoration: none;
  font-size: 1.2rem;
  font-weight: 650;
  letter-spacing: 0.02em;
}
.brand span {
  display: block;
  margin-top: 0.28rem;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 450;
  line-height: 1.6;
  letter-spacing: 0;
}
nav.primary {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1rem;
  margin-top: 0.85rem;
  font-size: 0.9rem;
}
nav.primary a { color: var(--ink); text-decoration: none; }
nav.primary a[aria-current="page"] { border-bottom: 1px solid var(--mark); }
.wrap { max-width: 44rem; margin: 0 auto; padding: 1.6rem 1.25rem 2.4rem; }
.kicker {
  margin: 0;
  color: var(--mark);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
}
h1 {
  font-size: 1.65rem;
  line-height: 1.4;
  font-weight: 650;
  margin: 0.35rem 0 0.9rem;
}
.lead {
  color: var(--muted);
  margin-top: 0;
}
h2 { font-size: 1.08rem; margin: 1.5rem 0 0.35rem; }
p { margin: 0.75rem 0; }
ul { padding-left: 1.15rem; }
li { margin: 0.28rem 0; }
.note, .src {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 3px solid var(--mark);
  padding: 0.75rem 0.95rem;
  margin: 1rem 0;
}
.src { color: var(--muted); font-size: 0.92rem; }
nav.index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.85rem;
  margin-top: 1.8rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line);
  font-size: 0.82rem;
}
nav.index a { color: var(--muted); text-decoration: none; }
nav.index a[aria-current="page"] { color: var(--ink); }
footer.site {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.82rem;
  max-width: 44rem;
  margin: 0 auto;
  padding: 1rem 1.25rem 2rem;
}
footer.site a { color: var(--muted); }